An Experimental Study on the Quenching of Flame by Narrow Cylindrical Passage

Abstract

To clarify the quenching characteristics of flame for a narrow cylindrical passage, the critical velocity of flame likely to ignite the outer mixture over a passage exit was investigated in relation to the dimensions of the passage. As the result of experiment, it was found that there existed two critical velocities of flame for given dimensions of passage in lower and considerably higher ranges of velocities. After some discussions about two critical limits from several points of view, it was shown that the lower limits were mainly concerned with cooling effect in passage and the higher limits had close relation to the flow conditions of hot jet issuing from the passage, and that in the latter case, quenching of flame by turbulent eddies might be considered one of the possible mechanisms.